糯性水稻中蜡质基因第1内含子的剪接活性

以前的研究结果表明 ,非糯性的稻米中直链淀粉的含量与各品种中蜡质基因 (Wx)第 1内含子被剪接的效率有关 ,即剪接效率高的品种直链淀粉含量也高。为弄清糯米中不含直链淀粉是否也与此内含子剪接效率有关系 ,构建了蜡质基因启动子 (来自籼稻品种2 32 )、蜡质基因第 1内含子 [来自籼稻品种 2 32 (高直链淀粉含量的品种 )或粳稻品种寒丰 6 36 6 (中、低直链淀粉含量的品种 ) ]与GUS报告基因组成的两种嵌合基因 ,将含有这两种嵌合基因的质粒分别转化进粳性糯稻品种奉糯 5 93中 ,同时还分别转化进非糯性的籼稻品种特青和粳稻品种中花 11中作为对照 ,测定它们的抗性愈伤组织与转基因植株未成熟种子胚乳中的GUS酶活性。结果表明与在非糯性的籼稻和粳稻中一样 ,这两种嵌合质粒在不合成直链淀粉的糯稻中也有相当水平的表达。从此结果可以推测 ,糯稻品种有从嵌合基因的转录本中剪接蜡质基因第 1内含子的正常能力 ,而在糯稻中缺乏直链淀粉可能是糯稻蜡质基因第1内含子中的其它突变所造成的     

云南元江普通野生稻群体Wx基因(CT)_n重复序列和第1内含子G/T位碱基分析

对云南元江普通野生稻90个个体Wx基因区段内的重复序列(CT)n和第1内含子供体+1位碱基G/T分别进行了比较分析。结果表明云南元江普通野生稻3个居群中的90个单株在重复序列(CT)n和G/T位点纯合一致,没有多态性;其G/T位点碱基均为G;其重复序列(CT)n基因型与云南地方籼稻品种优势基因型相似但又有所区别。本研究结果为云南元江普通野生稻Wx基因利用和在稻种进化上的地位提供了信息。     

云南元江普通野生稻群体Wx基因（CT）n重复序列和第一内含子G/T位碱基分析

对云南元江普通野生稻(O.rufipogon)90个个体Wx基因区段内的重复序列（CT）n和第一内含子供体+1位碱基G/T分别进行了比较分析。结果表明云南元江普通野生稻三个居群中的90个单株在重复序列（CT）n和G/T位点纯合一致,没有多态性;其G/T位点碱基均为G;其重复序列（CT）n基因型与云南地方籼稻品种优势基因型相似但又有所区别。本研究结果为云南元江普通野生稻Wx基因利用和在稻种进化上的地位提供了信息。     

籼稻和粳稻中蜡质基因座位上微卫星标记的多态性及其与直链淀粉含量的关系

稻米直链淀粉是在由蜡质基因Wx编码的颗粒结合淀粉合成酶（GBSS）的催化下合成的。最近,在Wx基因的区段内发现了一段多态性微卫星序列（CT）n。对74个非糯籼稻和粳稻材料的（CT）n多态性进行了分析,并探讨了其与直链淀粉含量之间的关系。在74个品种（系）中共发现7种（CT）n片段（Wx等位基因）,即（CT）8,（CF）10,（CT）11,（CT）16,（CT）17,（CT）18,（Ch）19。在籼粳亚种间,不同（CT）n的分布存在差异较大：在籼稻中,以（CT）11和（CT）18为主,占92．6％,另有（CT）10和（CT）8各2份,（CT）17型1份;在粳稻中,以（CT）16、（CT）17为主,共占20份材料中的90．0％。在上述74个品种（系）中,以（CT）n表示的Wx基因型对稻米直链淀粉含量的决定系数R2达0．912,也即Wx基因型差异可解释这些材料直链淀粉含量变异的91．2％。还发现6份籼稻材料Wx座位上为杂合的（CT）18／（CT）11,其中2份为推广早籼优质品种浙9248和舟优903,并对其在遗传和育种研究中的意义作了探讨。     

水稻蜡质基因引导区的两个SSR序列与直链淀粉含量的相关性(英文)

分析了蜡质基因引导区的两个简单重复序列 (SSR) (CT) n 和 (AATT) n 在 74份水稻材料中的多态性及其与直链淀粉含量 (AC)的关系。这些材料包括了籼稻 (OryzasativaL .ssp .indica)、粳稻 (O .sativassp .japonica)和普通野生稻 (O .rufipogon) ,其AC值覆盖了栽培稻AC分布的整个范围。以 (CT) n 作标记检测到 8个等位基因 ,粳稻品种趋于含有重复数目较多 (n≥ 16 )的等位基因 ,重复次数较少 (n≤ 14)的等位基因只出现在籼稻中。 (AATT)n检测到 2个等位基因 ,野生稻中少数植株表现出杂合性。分析表明AC与这两个SSR序列基因型高度相关 ,高AC (>2 2 .0 % )品种具有 (CT)重复次数较少 (n≤ 14)的等位基因 ;相反 ,除了糯米外 ,所有低或者中等AC的品种都有 (CT)重复数较多 (n≥ 16 )的等位基因。具有重复次数较多的 (AATT) 6等位基因的品种多为高AC ,具有重复次数较少的(AATT) 5等位基因的品种多为低或中等AC。不同SSR基因型品种间AC差异极显著。虽然目前还不能确定这两个SSR序列在直链淀粉合成中的直接功能 ,SSR变异与AC间近乎完全的相关性可作为分子标记直接用于水稻的品质改良。     

云南稻种资源多样性的生态地理分布研究

采用GIS、BioDiversity等技术,基于云南丰富的气候类型、特异的民族生境和多样的稻种资源条件,分析与观察了6081份云南地方稻种资源多样性在不同气候类型和各类稻区中的表现,结果表明：①不同气候环境对稻种资源的资源量和多样性的形成有显著作用。②稻种多样性从北热带→南亚热带→中亚热带→北亚热带→南温带→中温带→北温带逐渐减小。反之增大,结合各气候带的海拔和温度变化规律看,随海拔升高、温度降低而减小,反之亦然。籼粳亚种的多样性与稻种多样性呈现同样趋势。早、中、晚稻多样性在南温带、北热带和中亚热带相对较大;水、陆稻多样性在北热带、南亚热带和北亚热带相对较大;而与饮食文化相关的粘糯、特种稻多样性富聚区主要集中在北热带地区。③根据稻种多样性在各气候带中的分布可分为：低富聚气候带（指中温带和北温带）和富聚气候带（指北热带、南亚热带、中亚热带、北亚热带和南温带）。④稻种多样性在各类稻区中呈现：水、陆稻区〉单、双季籼稻区〉一季粳、籼稻区〉一季粳稻区。     

栽培稻种子含氮量的基因型差异

采用田间试验研究了421个常规籼稻、63个常规粳稻和82个籼型杂交稻品种种子含氮量的基因型差异。结果表明,栽培稻种子含氮量变幅在0.85%~2.55%,平均为1.39%。种子平均含氮量最高的是籼型杂交稻,高达1.46%,显著高于常规粳稻(1.39%)和常规籼稻(1.37%)。不同类型的栽培稻种子含氮量呈正态分布,但频数分布最高的区间存在一定的差异。以50%品种的种子含氮量(累积百分数从25%~75%)为依据,常规籼稻、常规粳稻、籼型杂交稻分别集中在1.21%~1.52%、1.21%~1.51%、1.36%~1.53%。LSR测验表明,籼型杂交稻极差显著小于常规籼稻和常规粳稻,但常规粳稻与常规籼稻的差异未达显著水平,即籼型杂交稻种子含氮量比常规籼稻和常规粳稻的分布更加集中。不同类型栽培稻内的种子含氮量极差较大,可分为若干组,且各组间达极显著差异。     

抗稻瘿蚊水稻品种的筛选鉴定研究

本研究就收集到的包括籼稻、粳稻、糯稻、陆稻、杂交稻和野生稻在内的水稻品种资源共13037份,采用先室内后田间,先苗期后分蘖期的筛选鉴定方法对稻瘿蚊的抗性进行了鉴定。选出了高抗级品种4个,抗级品种15个。同时还通过试验研究探知稻种抗稻瘿蚊害的机制是属于抗生性类型,与品种的物理性状关系不大。     

栽培稻及其近缘野生种间杂交揭示杂草稻的起源

通过水稻种间、亚种间和品种间的杂交,在套袋隔离和自然授粉两种条件下,对其杂交亲本主要农艺性状类型及杂交后代群体中杂草稻发生频率、类型及主要特征以及杂草稻的发生趋势进行调查分析,直接验证和重演杂草稻起源的主要路径。杂草稻的主要特征为:颖壳褐色或金色,种皮红色,散穗、易落粒,中长芒或无芒。结果表明,如果以近缘野生种为亲本,在其F2群体中比较容易发生类似杂草稻的单株;杂交组合中杂草稻出现频率的大小依次为:杂草稻或野生稻/粳稻(44.16%)>杂草稻或野生稻/籼稻(27.84%)>籼稻/粳稻(3.30%)>籼稻/籼稻(1.41%)>粳稻/粳稻(0)。这一结果显示杂交亲本间遗传差异越大,在后代中出现杂草稻类型植株的频率就越高。套袋条件下,后代中杂草稻出现的频率为10.70%,而不套袋情况下为4.90%。     

水稻长日抑制基因PhyB的多样性及区域适应性初探

Phy 是在长日照条件下抑制水稻开花的关键基因,但目前对水稻PhyB基因的遗传基础还不清楚,研究其分子遗传机制,对于培育光周期适应性广的品种以及扩大水稻种植区域具有重要意义。本研究选择78份亚洲栽培稻(34份籼稻和44份粳稻)及47份野生稻进行测序,对Phy B基因的核苷酸多态性、单倍型进行分析,计算籼稻、粳稻和野生稻的遗传多样性。结果表明,Phy B基因共有28个单倍型,其中有2个高频率的单倍型分别存在于2个栽培稻亚种中。从Network图可以看出栽培稻分为2组(A组和B组),A组栽培稻包括全部的籼稻和4个粳稻个体,B组栽培稻全是粳稻品种。亲缘地理学分析发现,A、B两组栽培稻具有明显不同的地理分布格局,且A组和B组开花时间差异显著,说明Phy B基因的2个高频率单倍型在2个栽培稻亚种中具有区域适应性,Phy B基因在栽培稻中具有明显的驯化信号,随着水稻种植区域的扩大,进化出适应不同地域特有的等位基因,导致开花时间对不同地区的区域适应性及多样性。     

Genetic structure and phylogeography of rice landraces in Yunnan, China, revealed by SSR.

Yunnan Province is one of the largest centers of genetic diversity of Oryza sativa L. in China, and in the world. Using a genetically representative core collection of 692 rice landraces from Yunnan, the genetic structure, differentiation, and geographic diversity of this rice germplasm were analyzed. The accessions were classified into different populations, according to the model-based structure analysis. Model-based populations were characterized through the reconstruction of a neighbor-joining tree, principal coordinate analysis, and the estimation of morphologic and SSR variations. Finally, the distribution of genetic diversity and differentiation among districts were studied. Seven model-based populations were identified on the basis of the structure analysis. This classification was partly consistent with Ting's 5-level taxonomic system. Differentiation between 2 rice subspecies is the most apparent, with a clearer differentiation between soil-watery ecotypes in japonica than in indica; however, differentiation among seasonal ecotypes in indica is clearer than in japonica. Cropping system and man-made restricted-growth environments could be considered to be the main forces driving the intraspecific differentiation of cultivated rice. It has been suggested that, because it possesses the highest genetic diversity and all the necessary conditions as a center of genetic diversity, the southwest region of Yunnan, encompassing Simao, Lincang, and Xishuangbanna districts, is the center of genetic diversity of Yunnan rice landraces.     

Genomic landscape of parallel domestication of upland rice and its implications

Parallel domestication has been widely acknowledged but itsgenetic basis remains largely unclear. As an important rice ecotype, upland rice was assumedly domesticated multiple times in two rice subspecies (Indica and Japonica) and provides a feasible system to explore the genetic basis of parallel domestication. To uncover the genome‐wide pattern of genetic differentiation between upland and lowland rice and explore the parallelism of genetic changes during upland rice domestication, we obtained whole‐genome sequences of 95 rice landraces and yielded genome‐wide expression data for five tissues of representative accessions of upland and lowland rice. Our phylogenetic analyses confirmed multiple domestications of the upland ecotype in two rice subspecies. Genomic scans based on resequencing data identified substantial differentiation between the upland and lowland ecotypes with 11.4% and 14.8% of the genome diverged between the two ecotypes in Indica and Japonica, respectively. Further genome‐wide gene expression analyses found that 30% of effectively expressed genes were significantly differentiated between two ecotypes, indicating the importance of regulation changes in the domestication of upland rice. Importantly, we found that only 1.8% of differentiated genomes and 1.6% of differentially expressed genes were shared by upland Indica and upland Japonica, suggestive of largely unparallel genetic alterations during upland rice domestication. These findings not only provide new insights into the genetic basis of parallel domestication at the genome scale but could also facilitate geneticimprovement and breeding of rice and crops in general.     

云南栽培稻种SSR 遗传多样性比较

采用64个SSR标记对96份云南水稻(Oryz a sativa)地方品种和选育品种的遗传多样性进行比较分析。结果发现64个标记都具有多态性, 共检测到741个等位基因, 每个多态性位点检测到的等位基因数为2-29个, 平均11.57个; Nei基因多样性指数(He)范围在0.345(RM321)-0.932(RM1)之间, 平均为0.56。水稻品种的遗传多样性并非按地理位置均匀分布, 而是在相 似系数为0.17的水平上明显分为2个不同类群, 即籼稻类群和粳稻类群, 且籼粳亚种间的SSR多样性差异不明显, 籼稻平均等位基因数(Ap)和Nei基因多样性指数(Ap=10.6, He=0.46)与粳稻品种(Ap=10.7, He=0.48)十分接近, 可能与这些品种间存在一定频率的基因交流有关。糯稻和非糯稻在籼稻群和粳稻群中都有表现, 没有特别的分布规律。云南栽培稻选育品种与地方稻亲缘关系较近, 其遗传基础可能来源于云南水稻地方品种。本研究结果表明, SSR标记能较好地区分云南栽培稻品种, 且云南水稻地方品种遗传多样性丰富, 存在大量的优质性状可供育种实践选择。     

Elemental Content in Brown Rice by Inductively Coupled Plasma Atomic Emission Spectroscopy Reveals the Evolution of Asian Cultivated Rice

The phylogenetic relationship for classification traits and eight mineral elements in brown rice (Oryza sativa L.) from Yunnan Province in China was carried out using microwave assisted digestion followed by inductively coupled plasma atomic emission spectroscopy, and the analytical procedures were carefully controlled and validated. In general, the results show that the mean levels of K, Ca, Mg, Fe and Cu in brown rice for 789 accessions of rice landraces was distinctly lower than that of improved cultivars. They further demonstrate that Ca plays an important role in the differentiation of subspecies indica-japonica, especially to enhance adaptation of cold stress, and that five mineral elements in brown rice enhance the eurytopicity from landrace to improved cultivar. Hierarchical cluster analysis, using average linkage from SPSS software based on eight mineral elements in brown rice, showed that Yunnan rice could be grouped into rice landrace and improved cultivar, with the rice landrace being further clustered into five subgroups, and that, interestingly, purple rice does not cluster with either of the groups. Our present data confirm that indica is the closest relative of late rice and white rice, and that they constitute rice landraces together, whereas japonica is the closest relatives of non-nuda, early-mid and glutinous rice. It is further shown that japonica, non-nuda, early-mid, glutinous, white and red rice might be more primitive than indica, nuda, late, non-glutinous and purple rice, respectively.     

云南栽培稻种SSR遗传多样性比较

采用64个SSR标记对96份云南水稻（Oryza sativa）地方品种和选育品种的遗传多样性进行比较分析。结果发现64个标记都具有多态性,共检测到741个等位基因,每个多态性位点检测到的等位基因数为2—29个,平均11．57个：Nei基因多样性指数（He）范围在0．345（RM321）-0．932（RM1）之间,平均为0．56。水稻品种的遗传多样性并非按地理位置均匀分布,而是在相似系数为0．17的水平上明显分为2个不同类群,即籼稻类群和粳稻类群,且籼粳亚种间的SSR多样性差异不明显,籼稻平均等位基因数（Ap）和Nei基因多样性指数（Ap=10．6,He=0．46）与粳稻品种（Ap=10．7,He=0．48）十分接近,可能与这些品种间存在一定频率的基因交流有关。糯稻和非糯稻在籼稻群和粳稻群中都有表现,没有特别的分布规律。云南栽培稻选育品种与地方稻亲缘关系较近,其遗传基础可能来源于云南水稻地方品种。本研究结果表明,SSR标记能较好地区分云南栽培稻品种,且云南水稻地方品种遗传多样性丰富,存在大量的优质性状可供育种实践选择。